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Antonios Sideris

Publications and source records attributed to Antonios Sideris.

14 recordsLinked to original sources

ST-segment elevation induced during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation.

We report two cases of transient coronary artery ischemia manifested as chest discomfort with ST-segment elevation in inferior leads during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation. This unexpected complication was resolved by intravenous administration of nitrates. All patients exhibited normal coronary arteries in angiography. A neurally mediated pathway activated by the mechanical effects of the transseptal puncture on the interatrial vagal network leading to coronary artery spasm may be considered as a possible explanation of this phenomenon. Coronary artery embolism following the transseptal procedure represents a different underlying mechanism.

Atrial Fibrillation↗

Secondary prevention of sudden cardiac death in coronary artery spasm: is implantable cardioverter defibrillator always efficient?

Syncope and/or cardiac arrest in the setting of coronary artery spasm have been associated with atrioventricular block and asystole or ventricular tachyarrhythmias. Ventricular arrhythmias have been predominantly reported in cases of multivessel coronary artery spasm. The present report highlights the case of a young woman who suffered repeated episodes of multivessel coronary artery spasm in association with polymorphic ventricular tachycardia and cardiac arrest. The efficacy of implantable cardioverter defibrillator in secondary prevention of sudden cardiac death due to coronary artery spasm is discussed.

Adult↗

Swimming-triggered aborted sudden cardiac death in a patient with Andersen-Tawil syndrome.

In this report we describe the case of a 42-year-old woman who experienced an episode of near drowning during recreational swimming. A diagnosis of Andersen-Tawil syndrome was made based on the patient's dysmorphic features, characteristic T-U-wave patterns and ventricular arrhythmias. To our knowledge, this is the first report of a swimming-triggered cardiac event in a patient with Andersen-Tawil syndrome.

Adult↗

Early repolarization syndrome: is it always benign?

Early repolarization syndrome is a well-recognized idiopathic electrocardiographic phenomenon characterized by prominent J wave and ST-segment elevation predominantly in left precordial leads. The syndrome shares remarkable cellular, ionic, and electrocardiographic similarities with the Brugada syndrome and idiopathic ventricular fibrillation (a variant of the Brugada syndrome with ST-segment elevation in inferior leads). Although early repolarization syndrome is considered a benign entity, its arrhythmogenic potential still remains unknown. We report the case of a 39-year-old male with a family history of sudden death and an electrocardiogram consistent with early repolarization syndrome. Diagnostic dilemmas are discussed.

Adult↗

Pathophysiology and management of syncope in Kearns-Sayre syndrome.

A 20-year-old woman with known Kearns-Sayre syndrome was transferred to the emergency department due to syncopal episodes. The electrocardiogram on admission showed complete atrioventricular block. The diagnosis of mitochondrial encephalomyopathy was made when she was 14 years old. At the time of the initial diagnosis, she displayed a normal electrocardiogram pattern. At the age of 17, electrocardiogram recordings demonstrated right bundle branch block with left anterior fascicular block and a prolonged QTc interval of 485 milliseconds (Figure). She was taking coenzyme Q10, oral nicotinamide adenine dinucleotide (reduced), piribedil, amantadine, and primidone. Transthoracic echocardiography revealed normal wall motion of both ventricles and mitral valve prolapse without regurgitation. A permanent dual-chamber pacemaker was immediately implanted.

Adult↗

Hypertrophic cardiomyopathy in a patient with Crohn's disease: a case report.

Cardiac manifestations of Crohn's disease are rare; the most common is pericarditis. In the present report we briefly describe a 56-year-old man with Crohn's disease who presented to the emergency department due to paroxysmal atrial flutter. A transthoracic echocardiographic study revealed asymmetric left ventricular hypertrophy without outflow pressure gradient. Reviewing the literature, hypertrophic cardiomyopathy has not been previously described in patients with Crohn's disease.

Cardiomyopathy, Hypertrophic↗

QT interval prolongation and torsade de pointes associated with indapamide.

Direct blockade of the delayed rectifier repolarising potassium current is the major underlying mechanism of drug-induced QT interval prolongation. Indapamide is a well known blocker of the slow component of the delayed rectifier current leading to prolongation of cardiac repolarization. The case of an acquired long QT and torsade de pointes ventricular tachycardia in a woman with systemic lupus erythematosus and hypertension receiving prednisolone and indapamide, respectively, is described in the present report.

Adult↗

Exercise-induced second-degree atrioventricular block.

In this report we describe the case of a 56-year-old woman with normal 1:1 AV conduction at rest who developed 2:1 AV block during treadmill exercise testing. Electrophysiological study documented 2:1 AV block proximal to the His bundle with reappearance of 1:1 AV conduction at a higher pacing atrial rate. A gap phenomenon involving a proximal and distal part of the AV node may be a likely explanation of paradoxical AV conduction in our case.

Bundle of His↗

Drug-induced QT interval prolongation after ciprofloxacin administration in a patient receiving olanzapine.

Several non-antiarrhythmic drugs including antibiotic and antipsychotic agents have been shown to prolong cardiac repolarization predisposing to torsade de pointes ventricular tachycardia. Blockade of the delayed rectifier (repolarising) potassium current and drug interactions with inhibitors of the CYP-mediated metabolism are the most common underlying mechanisms. In the present case report, an elderly woman receiving a long-term medication with azathioprine, olanzapine and valsartan developed a marked QT interval prolongation after intravenous administration of ciprofloxacin.

Aged↗

QT interval prolongation and torsades de pointes due to a coadministration of metronidazole and amiodarone.

This report documents the occurrence of torsades de pointes (TdP) caused by marked QT interval prolongation in the case of a 71-year-old woman receiving both metronidazole and amiodarone for the treatment of pseudomembranous colitis and paroxysmal atrial fibrillation. The case highlights a previously unknown drug interaction. The role of inhibition of cytochrome P-450 CYP3A4 is discussed.

Aged↗

Cadmium effects on brain acetylcholinesterase activity and antioxidant status of adult rats: modulation by zinc, calcium and L-cysteine co-administration.

We have previously reported that cadmium (Cd) as 3CdSO4 . 8H2O decreases rat brain total antioxidant status and L-cysteine (Cys) has a protective effect against it. The aim of the present study was to investigate the effects of subacute Cd administration, either alone or (almost simultaneously) with zinc (Zn), calcium (Ca) and Cys, on brain acetylcholinesterase (AChE) activity and brain total antioxidant status in male adult rats. All substances were administered intraperitoneally. Cadmium (1 mg/kg/day for 14 days) increased AChE activity (+46%; P<0.001) and decreased total antioxidant status (-29%; P<0.001). Zinc and Ca (both 1 mg/kg/day for 14 days) increased AChE activity (+18%; P<0.01 and +53%; P<0.001) and caused no changes on rat brain total antioxidant status. L-Cysteine (7 mg/kg/day for 14 days) impressively increased AChE activity (+185%; P<0.001) and augmented total antioxidant status (+26%; P<0.001). In the groups of Zn+Cd, Ca+Cd and Cys+Cd co-administration, AChE activity remained high (+42%; P<0.001, +41%; P<0.001 and +141%; P<0.001 respectively), while total antioxidant status returned to the saline control levels. L-Cysteine given before a toxic dose of Cd (5 mg/kg) resulted in high AChE activity (+85%; P<0.001), a total antioxidant status similar to the control values, and survival of the treated rats. In conclusion, Cd increased brain AChE activity and decreased brain total antioxidant status of adult male rats. Zinc, Ca and Cys, given just before Cd administration, modified the Cd-induced effects and restored rat brain total antioxidant status to the control levels.

Acetylcholinesterase↗

Effect of atrial pressure increase on sinus node automaticity.

There is evidence suggesting that atrial electrophysiological properties may be changed by an acute increase in atrial pressure. The aim of the present study was to investigate the effect of alteration, in atrial pressure on sinus node recovery time. Twelve patients (8 men and 4 women, mean age 61.3 +/- 14.1 years) were included in this study. None of the patients had organic heart disease. Sinus node recovery time (SNRT) was measured following atrial pacing and atrioventricular (AV) pacing at sequential cycle lengths of 600, 545, 500, 461, 428, and 400 ms with two different AV intervals (150, 0 ms). Peak and minimal atrial pressure increased significantly from 8.5 +/- 2.8 to 20.1 +/- 2.9 mmHg (11.56 +/- 3.8 to 27.3 +/- 3.9 cmH2O) ( P=0.001) and from 2.06 +/- 1.69 to 5.33 +/- 2.9 mmHg (2.8 +/- 2.29 to 7.2 +/- 3.9 cmH2O), respectively (P=0.002) during AV interval modification. Sinus node recovery time did not change despite the increase in atrial pressure. Autonomic blockade had no effect on SNRT. This study demonstrates that atrial pressure increase does not significantly affect sinus node automaticity expressed by SNRT.

Adult↗